Comparison of the Lever Sign Test, Anterior Drawer Test and Lachman Test in Cases of Anterior Cruciate Ligament Tear: A Prospective Cohort Study

Abstract

Introduction: The Anterior Cruciate Ligament (ACL) is a very commonly injured ligament of knee. Several physical examination tests are performed for evaluating ACL stability. The Lachman, pivot-shift, and anterior drawer tests are commonly performed for evaluating the knee laxity. Aim: To compare Lever sign test with anterior drawer test and Lachman test in case of ACL tear, and to assess preanaesthesia and postanaesthesia variability in tests results. Materials and Methods: This prospective cohort study was conducted at Government Medical College, Kathua, Jammu, India, from October 2018 till September 2019. Total 50 patients were included (age group 18-60 years) with symptomatic ACL tear requiring diagnostic arthroscopy or repair. Three tests Lever sign test, anterior drawer test and Lachman test were performed preanaesthesia and postanaesthesia and findings were recorded. Sensitivity and specificity was calculated preanaesthesia and postanaesthesia. Statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 21.0. The p-value ≤0.05 was considered statistically significant. Results: Total 50 patients were evaluated and analysed including 60% males (n=30) and 40% females (n=20). The mean age of the patients was 34.5±2.6 years. Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Values (NPV) and diagnostic accuracy of anterior drawer test preanaesthesia were 83%, 87%, 97%, 50%, and 84%, respectively, and postanaesthesia were 88%, 87%, 97%, 58%, and 88%; for Lachman test preanaesthesia were 88%, 87%, 97%, 58%, and 88%, respectively, and postanaesthesia were 90%, 87%, 97%, 63%, and 90%; and for Lever sign test preanaesthesia were 85%, 88%, 100%, 57%, and 88%, and postanaesthesia were 88%, 100%, 100%, 61%, and 90%, respectively. There was no significant difference in the diagnostic accuracy of the three tests while comparing for preanaesthesia and postanaesthesia or for individual tests (p>0.05). Conclusion: The lever test showed high specificity, but comparable diagnostic accuracy in the detection of ACL tears in comparison to anterior drawer test and Lachman test. All the tests hold equal importance for diagnosing ACL tears before and after anaesthesia.